Mr.  fa55tbenz 
  
Yes you can do it. 
  
1- do u have jus 2 cameras right now? 
Yes, continue... 
  
No, no you can not install more, cose' dv 9240 is only for four cameras. 
  
If you need adding 2 cameras, you will need coax cable for each one camera and dc adapter. 
then... check your software setup configuration. 
Enable the 2 channels to new cameras installed. 
  
Have agood luck! 
  
Check this: 
Eyemax downloads 
http://www.eyemaxdvr.com/scripts/quickdownload.asp 
  
Section recommended: 
Older Version of Software and Manual to download.